The present invention relates to probes for use with systems for detecting underground gas leaks from conduit systems. More particularly, the present invention relates to improvements in gas probes which are inserted into the ground for sampling subsurface gases.
In conventional systems for detecting leaks in underground conduit systems, it is common to utilize gas detectors for locating underground leaks. The testers involve the use of a probe for sampling underground gases which is connected through a conduit to a gas detection device. A typical gas detection is the D-15 Gastester manufactured by Scott Davis Instruments of Lancaster, New York.
When underground conduits are present, it is necessary to gain access to the area surrounding these underground conduits. A small opening which terminates on the exterior surface of the conduit is formed in the soil. This can be accomplished using an impact bar. Thereafter, a probe on the end of the length of the conduit is inserted through the opening to a point adjacent to the underground conduit. A sample of the underground gas adjacent to the conduit is collected through the probe and is transported up through the conduit to the gas tester device to determine the presence of undesirable gases which would be present around a gas leak.
Although these conventional systems detect gas leaks in many environments, they have not been entirely satisfactory under all conditions of service because of the tendency of conventional gas probes to plug up during insertion into the ground. This is especially true when the operation is being performed in moist soils which easily extrude into the probe.